Supercharger system for internal combustion engines



Sept. 15, 1959 J. R. BOYD 2,903,847

SUPERCHARGER SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Nov. 2, 1955Air Cleaner rbo- 5U perc ho rger O 67 ln+rnol Combusiion 71 66 Engine 22a i? L Info e manifold 2b 9 INVENTOR.

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United StatesPatent Q SUPERCHARGER SYSTEM FOR INTERNAL CONDBUSTIONENGINES John Robert Boyd, Venice, Calif.

Application November 2, 1953, Serial No. 389,557

9 Claims. (Cl. 60-13) This invention relates to superchargers forinternal combustion engines and especially to superchargers of the typecomprising a centrifugal compressor driven by a turbine operated by theexhaust gases from the engine being supercharged.

The prime object of the invention is to provide a supercharger of theabove type which is sufficiently compact to enable same to beaccommodated in the existent clearance space within the enginecompartment of standard automobiles.

Another object of the invention is to provide an improved superchargerof the above type which is of simple construction to enable same to bemanufactured inexpensively and installed on an automobile easily.

Another object of the invention is to provide a simplifiedturbo-supercharger having a single compressor wheel which will operatemore efliciently than heretofore possible.

Still another object of the invention is to provide a turbo-superchargersystem of the above type which in cludes simplified means whereby itseffectiveness for a given engine exhaust pressure may be regulatedaccording to the load on the engine being supercharged.

Still another object of the invention is to provide a turbo-superchargersystem which will operate efficiently at low engine speeds withoutinducing a high engine exhaust pressure at the engine exhaust valves.

Other objects and advantages of the invention will become apparent fromthe following description thereof taken in connection with the drawing,in which, Fig. 1 isa side elevation view showing a turbo-superchargerinstalled on an internal combustion engine; Fig. 2 is an exposedelevation view, partly in outline and partly in section, showing thestructural details of my novel turbosupercharger; Fig. 3 is a view,partly in outline and partly in section, taken along the lines 33 inFig. 2 to show details of my turbo-supercharger not disclosed in Fig. 2;Fig. 4 is a side elevation view, partly in outline and partly insection, showing my manual novel supercharger as installed on aninternal combustion engine and including means in the form of an ejectorfor assuring maximum pressure drop across the turbine portion of suchsupercharger at low engine speeds without inducing high mean exhaustpressure at the engine exhaust ports; and

Fig. 5 shows in schematic form the shape of the path of flow of exhaustgases through the turbine portion of my turbo-supercharger. i

Referring particularly to Fig. 2 in the drawing, according to onefeature of my novel turbo-supercharger, the casing 1 containing theturbine wheel 2 is itself contained within the casing 5 for thecompressor impeller 6 driven by said turbine wheel, thereby affording,as shown in Fig. 1, an extremely compact arrangement of no greaterheight than that of the usual intake air cleaner included on internalcombustion engines, thus enabling said turbosupercharger to beinterposed directly between the carburetor of said engine and the intakemanifold on the 2,903,847 7 Patented Sept. 15, 1959 engine withoutinterference with the engine hood; the usual air cleaner being suitablymounted at one side of the turbo-supercharger and carburetor assemblageand connected to the latter through the medium of the usual flexibleduct tubing. i

Referring to Figs. 2 and 3, the casing 1 is provided with the usualcylindrical chamber 7 in which is disposed the turbine wheel 2; saidwheel having a plurality of the usual circumferentially spaced-apartblades 8 integrally attached to the usual disk-shaped rotary hub 9 andprojecting from said hub in an axial direction for slight clearancebetween same and the peripheral Wall 11) of said chamber. The casing 1is further provided with an inlet or nozzle 11 opening into the wall 10to allow for admittance of engine exhaust gases into chamher 7 via theblades 8 of the turbine wheel; an outlet opening 12 through said wallbeing provided in casing 1 to allow for exit of the engine exhaust gasesfrom chamber 7 via passage through the turbine wheel blades 3 a secondtime.

Referring particularly to Fig. 3, the inner turbine casing 1 is joinedwith the outer compressor casing 5 in the region of the turbine inletand outlet openings 11 and 12, otherwise the two casings 1 and 5 areseparated one from the other to provide a segmental annular clearancespace 15 for permitting flow of fluid under pressure there-past.

Referring now particularly to Fig. 2, as shown in the drawing, the upperend of the casing 5 serves as an inlet to the compressor impeller 6 andis adapted for registry with the outlet 16 of the carburetor which is tobe mounted directly thereon. The impeller 6 disposed within the upperportion of the casing 5 comprises the usual blades 17 which operate incooperation with said casing portion to withdraw the carbureted mixtureof air and fuel from the carburetor and discharge same via the clearance15 and the lower portion of casing 5 into the intake manifold of theengine by way of registering openings 20 and =21 in such portion andmanifold, respectively. Spaced-apart diffuser vanes 18 extending betweencasings 1 and 5 are disposed in the segmental clearance spaces 15 toproperly direct such discharge from the impeller wheel 6.

According to the feature of compactness of my novel turbo-charger, theblades 17 of the impeller 6 are disposed about the outer periphery of atapered central hub portion 19 having its apex disposed at the inlet tothe upper portion of casing 5 and its base portion in proximity of andin coincidence with an end Wall 26 of the turbine casing 1; such hubportion thereby acting as a diffuser directing flow from said inlet tothe clearance spaces 15 during operation of the impeller. The blades 17are spaced-apart circumferentially of the hub 19 to which they aresuitably attached and extend in an axial direction from the apex of saidhub to the base portion in alignment with the bottom face thereof. Theinner peripheral surface of the upper portion of casing 5 follows, ingeneral, the contour of the hub 19 of the impeller, and the outer edgesof the blades 17 of said impeller follow the contour of said innersurface and are in close proximity thereto.

For sake of illustration, the impeller 6 of the compressor portion ofthe turbo-supercharger may be operably connected to the turbine wheel 2of the turbine por tion through the medium of such as a shaft 22suitably journaled at the inlet end of the compressor as by means of ajournal 23 supported by a spider 24- in said inlet and at the oppositeend by means of a journal 25 suitably mounted in the respective end wall26 of the turbine casing 1.

Referring to Figs. 2 and 3, according to another feature of theinvention, the turbine portion of my novel turbosupercharger is providedwith an element 30 disposed within chamber 7 and within the circulararea therein defined by the inner peripheral edges of the blades 8 ofthe turbine wheel 2. The upper peripheral surface of element 30 definesthe inner contour of the area available for flow of exhaust gases fromthe engine through the turbine, and which element 30 may be madeadjustable to' different angular positions relative to the turbine inletnozzle 11, as indicated in Fig. 3 by the dash outlines, to regulateadmittance of exhaust gas from the engine via inlet nozzle 11 to andthrough the turbine. Element 30, as viewed in Fig. 2, is of sufficientthickness as will substantially fill the axial space between the hubportion 9 of the turbine wheel 2 at the upper side of said element 30and the end wall 31 of turbine casing 1 at the lower side of saidelement, thereby to assure that the engine exhaust gases admitted vianozzle 11 to the chamber 7 will not by-pass the element, 30 en route toturbine outlet 12. The profile of element 30 radialwise of a shaft 33 onwhich it is mounted, is in the form of a modified elipse having a roundbottom surface 34 corresponding to the curvature of; the innerperipheral surface of the turbine blades 8 and formed on a radius ofcurvature centering at the axis of shaft 33 so as not to interfere withthe movement of the turbine blades 8 about said surface 34 regardless ofthe angular position of element 30 relative to shaft 33. The surface 34of control element 30 merges with a gently rounded surface 35 at theupper side of said control element 30, as viewed in the drawing, via arouuded surface of a portion 36 of element 30 projectiug from the shaft33 at one side in the direction of the inlet nozzle 11, and with saidsurface 35 on the opposite side of said shaft 33, by way of a roundedsurface of a portion 37 extending from said shaft in the direction ofthe outlet opening 12. The surface 35 of element 30 defines the innerperipheral surface for the direction of flow of engine exhaust gasesthrough he c n Referring to Figs. 3 and 5, according to a feature of myinvention, by virtue of the disposition, arrangement and configurationof the inlet nozzle 11, element 30, and outlet 12 relative to theturbine wheel 2, the engine exhaust gases admitted to the turbine areconducted en route to outlet 12 first through a convergent conduit theform of the inlet nozzle 11, then through a divergent-convergent conduitdefined by the inner surface of casing 1 and the surface 35 of element30 in which substantially more than half of the turbine wheel 2disposed. By virtue of the convergent, divergent, convergent flow pathabove, the exhaust gases passing through the turbine can be made toattain a substantially constant. supersonic velocity in thedivergent-convergent region, in which the turbine wheel is disposed, atsubstantially all turbine inlet, or engine exhaust, pressures for anygiven position of element 30. The divergentconvergent region extendsalong a curvilinear path between inlet and outlet of the turbine todirect the high velocity gases along a circumferential path, a path inthe direction in which the turbine wheel 2 rotates, to extract from suchhigh velocity gases a maximum amount of work in the form of rotation ofsuch wheel at high velocity.

According to another feature of the invention, the

portion 36 of element 30 projecting in the direction of inlet nozzle 11from one side of the shaft 33 may be made longer than the portion 37 ofelement 30 projecting in the direction of outlet 12 from the oppositeside of shaft 33, and the latter portion 37 'may be made more blunt withrespect to portion 36 for reasons which hereinafter will becomeapparent.

The inlet nozzle 11 is so disposed in the casing of the turbine as toopen to the interior thereof substantially tangentially of the turbinewheel 2. and in efiective alignment with the blades 8, while being sodisposed relative to the control element 30 that angular movement ofsaid element 30 to such as the position indicated by the dash line 40will advance portion 36 of said element 30 to a position in which flowof engine exhaust gases from nozzle 11 to the divergent-convergentregion in interior of the casing 1 by way of the blades 8 of the turbinewheel will be more restricted than otherwise attained in the position ofportion 36 in which it is shown in the drawing in solid outline, andless restricted when the portion 36 of element 30 is caused to assumethe position in which it is shown in dash outline 41 in the drawing. Theoutlet opening 12 is so adapted and arranged relative to the turbinewheel 2 as to allow for facile egress of exhaust gases from the turbine,and so disposed relative to the portion 37 of the control element 30that such facile egress will be relatively unaffected by movement ofsuch portion 37 to the different angular positions of the element 30 asaforedescribed.

The shaft 33 to which the control element 30 is attached may be suitablyjournaled in an accommodating opening provided in the end wall 31 ofcasing 1, and may be adapted for rotary movement to cause the element 30to assume its different angular positions through the medium of such asa worm driven gear arrangement 45 contained within a suitable housing 46attached to the casing 1 of the turbine and disposed within the lowerportion of the compressor casing 5; the gear portion of the worm andgear drive being attached to the shaft 33 and the worm portion extendingoutwardly to the exterior of the supercharger by way of a suitableopening (not shown).

According to another feature of the invention, the modification as shownin Fig. 4 includes an ejector nozzle 60 suitably housed and arranged toreceive exhaust gases from the engine in by-pass of the turbine portionof the turbo-supercharger to cause a suction to be generated at theoutlet 12 of the turbine portion of the supercharger by virtue of flowof engine exhaust gases through such ejector. The turbine inlet nozzle11 of the turbo-supercharger may receive engine exhaust gases or exhaustgases from the engine by way of a fluid conyeying meanssuch as amanifold 64 and a branch of said manifold 64. may form the inlet to theejector nozzle 60. A manifold 65 may serve as the connection from theoutlet 12 of the turbine portion of the supercharger to the usualejector housing 61 encircling the outlet of the ejector nozzle 60suitably arranged relative to a reduced section 66; of an ejectordiffuser section 67 as to cause the aforementioned suction at theturbine outlet by virtue of flow of engine exhaust gases through theejector nozzle 60 according to well-known principles of fluid flow.

For the purposes of controlling the effectiveness of the ejector nozzle60, as shown in Fig. 4, such as a conical-shaped, element 70 may beprovided for graduated movement into, and out of the outlet end of theejector nozzle to control or regulate flow of engine exhaust gasestherethrough. The element 70 may be attached to the usual linkage 71suitably arranged for actuation from a station exterior of the housing61 containing the ejector no le Operation Assume that the internalcombustion engine with whichmy. novel turbo-supercharger system isassociated is operating at a, normal load and speed; that the controlelement 30; of the turbine portion of my turbo-supercharger is intheposition in which it is shown in solid outline in Fig. 3 of thedrawing; and that the element 70 associated with the ejector nozzleshown in Fig. 4 is in a position relative to the outlet end of theejector nozzle 60 to close or partially close same. Under the assumedconditions, referring to the various figures of the drawing, the exhaustgases from the engine will flow byway of a branch of the manifold 64into the inlet nozzle 11 of the turbine portion of theturbo-supercharger and to the blades 8 of the turbine wheel throughwhich such gases will expand for the first time interior of the casing 1to attain super-sonic velocity in the divergent-convergent region, andthence pass through said blades for the second time to the manifold 65via outlet 12.

Such passage of engine exhaust gases through the turbine wheel 2 willoccur at a normal rate commensurate with the normal load conditions ofthe engine and as determined by the normal position of the controlelement 30 and will cause said turbine wheel to rotate at a particularspeed and in turn to drive the compressor impeller 6 at a rate alsocommensurate with the load and speed conditions of the engine to causecombustion air for the engine to be drawn in by way of the air cleanerinto the carburetor, where same is mixed in the usual fashion with fuel,to pass through said carburetor, through the blades 17 of the impeller 6within casing 5 and around the casing 1 of the turbine by way of theclearance space and guide vanes 18, into and through the lower portionof the casing 5 of the compressor, into and through the registeringopenings 20 and 21 of the casing 5 and engine intake manifold,respectively, for distribution in the usual fashion to the variouscylinders of the engine to maintain operation of same in an eflEicientmanner and at the assumed normal load and speed conditions thereof.

Referring to Fig. 4, at the same time, a portion of the gases beingexhausted from the engine will flow by way of the respective branch ofthe manifold 64, in by-pass of the exhaust gases passing through theturbine, to the ejector nozzle 60 where same will cause a suction to begenerated in the manifold 65 in aid of withdrawal and passage of exhaustgas through the turbine via the exhaust opening 12 and eventualdispensation of such gases to the atmosphere by way of the ejectordiffuser manifold 67 and such as the usual muffler and exhaust pipe (notshown) associated with an internal combustion engine. The efiect of theejector nozzle on the turbosupercharger will be such as to increase itsefiectiveness by encouraging the passage of exhaust gases through theturbine without increasing the back pressure at the engine exhaust. Theeffectiveness of the ejector nozzle 60 under normal load and speedconditions of the engine may more or less be arbitrarily determinedaccording to selective positioning of the control element 70.

Assume now, for the sake of illustration, that the internal combustionengine is being employed in such as an automobile and that same iscoasting down hill, in which case the load on the engine will be nil,while the engine will be turning over at average speed. Under suchcircumstances, it is desired to render the turbo-supercharger lesseffective in order that the amount of air drawn into the carburetor willnot cause an exceptional amount of fuel to be admitted to the enginewhich cannot be utilized under the assumed no-load condition. Accordingto a feature of the invention, the control element 30 associated withthe turbine will be caused to assume some position such as the positionin which it is shown in the dash outline 40 in Fig. 3 by adjustment inposition of the shaft 33 through the medium of the worm and geararrangement 45. By virtue of such movement of the control element 30toward or to its position 40, flow of exhaust gases from the respectivebranch of the manifold 64 will be relatively more restricted than in thenormal position of said element 30 and the mass flow of such gasesthrough the turbine will be reduced, with the result that the speed ofthe turbine wheel 2 will be correspondingly reduced as well as will bethe speed of the compressor impeller 6 driven by said turbine wheel sothat less air will pass through the carburetor and fuel consumption willbe reduced. At the same time, a greater portion of the exhaust gasesfrom the engine will pass via respective branch of the manifold 64through the used to advantage.

6 ejector nozzle 60 to the atmosphere by way of the ejector diffusermanifold 67. It will be understood that with the reduced admission offuel to the engine as a consequence of the throttle position and thereduced effectiveness of the turbo-supercharger, the pressure andeffectiveness of any exhaust gases leaving the engine will be greatlyreduced so that flow through nozzle 60 will not materially affect theeffectiveness of the turbine.

Assume now that the engine is operating at an increased load and/ orspeed, such as would correspond with travel of an automobile on thelevel at high speeds or at average speeds going up grade. Under suchcircumstances, it will be desired to increase the effectiveness of theturbosupercharger and the control element 30 will be caused to assumethe position in which it is shown in the dash outline 41 in Fig. 3 andin which position its portion 36 is retracted further away from theoutlet of the inlet nozzle 11 to allow for facile admittance of engineexhaust gases through the turbine, which in turn will result in anincreased flow of such gases therethrough and a consequent increase inspeed of the turbine wheel 2 and hence of the compressor impeller 6, aswell as an increase in the volume of air admitted from the atmosphere tothe engine intake manifold by way of the carburetor of my novelturbo-supercharger to cause the engine to more completely burn the fuelmixed with such air and therefore generate increased power commensuratewith the assumed load and/or speed conditions of the automobileemploying such system. Under such operating conditions of myturbo-supercharger, the adjusting element 70 associated with the ejectornozzle 60 may arbitrarily be positioned relative to the output of saidnozzle 60 to render same more or less effective to assist operation ofthe turbine according to desires.

Assume now that the engine is operating at low speed under average orhigh load conditions. Under such assumed conditions, it will be desiredto render the turbine portion of my turbo-supercharger maximallyefiective by movement of the control element 30 to the positionindicated by the dash line 41 to allow for facile admission of exhaustgases through the turbine by way of the respective branch of the exhaustmanifold 64, while at the same time it is desired that the back pressureimposed by flow of such exhaust gases through the turbine will notimpose an undue restraint at the engine exhaust ports which will act onthe engine in opposition to the effect of supercharging same. Underthese conditions, the ejector nozzle 60 shown in Fig. 4, will be Thecontrol element 70 will be moved to an open position to allow formaximum bypass flow of exhaust gases through the ejector which flow willcreate a minimal amount of back pressure on the engine exhaust portswhile at the same time greatly increase the effectiveness of the exhaustgases passing through the turbo-supercharger by virtue of increasing thediflerential in pressure between the input and output side of theturbine portion of said turbo-supercharger and thereby increase the workavailable from said gases and realized by said turbo-supercharger in theform of an increased output.

Having now described the invention, what I claim as new and desire tosecure by Letter Patent is:

1. In combination: an internal combustion engine having an air-fuelintake manifold and an exhaust gas manifold; a turbo-supercharger havingan inlet and outlet communicating with said exhaust gas manifold; saidturbo-supercharger defining between said inlet and outlet a relativelyconvergent, divergent and convergent flow path for exhaust gas passingtherethrough; and, a camlike control element mounted within saidturbo-supercharger for changing the area and curvature of said flowpath.

2. In combination: a fluid conduit connected to a variable source offluid under pressure, said fluid conduit dividing at a first junctionpoint into a first fluid passage a and'a second fluid passage downstreamof said source, said first fluid passage and said second fluid passagebeing joined together to re-establish said fluid conduit at a secondjunction point further downstream from said source; a turbine having aninlet and outlet communicating with said first fluid passage, saidturbine defining between said inlet and outlet a relatively convergent,divergent, and convergent flow path for fluid passing therethrough; acam-like control element within said turbine for changing the area andcurvature of said flow path; and, ejector nozzle means embodied in saidsecond fluid passage at said second junction point, said ejector nozzlemeans acting to create a pressure differential urging flow through saidfirst fluid passage towards said second junction point.

3. The combination of: an internal combustion engine having acarburetor, an air-fuel intake manifold and an exhaust manifold; aturbo-supercharger associated with said engine, said turbo-superchargercomprising a hollow casing containing both air compressing means andturbine means; said turbo-supercharger having an air-fuel inlet forpressure sealed mounting on an outlet end of said carburetor and anair-fuel outlet for pressure sealed mounting on an air-fuel inletportion of said air-fuel intake manifold, a portion of said exhaustmanifold I being divided at a first given junction point to form a firstfluid passage and a second fluid passage, said first fluid passage andsaid second fluid passage being joined together at a second givenjunction point downstream of said first given junction point tore-establish said exhaust manifold, said turbo-supercharger beinginterposed in and having an inlet and outlet communicating with saidfirst fluid passage whereby said turbine means is driven by gas flowingthrough said first fluid passage, said turbo-supercharger definingbetween said inlet and said outlet a relatively convergent, divergent,and convergent flow path for exhaust gas passing therethrough; and, acam-like control element within said casing for changing the area andcurvature of said flow path.

4. The combination according to claim 3, and ejector nozzle meansembodied in said second fluid passage at said second junction point,said ejector nozzle means acting to create a pressure differentialurging flow through said first fluid passage towards said secondjunction point.

5. The combination according to claim 4, and adjustable means forvarying the effective area of said ejector nozzle means relative to agiven quantity and pressure of exhaust gas admitted thereto through saidsecond fluid passage.

6. In combination: a fluid conduit connected to a variable source offluid under pressure, said fluid conduit dividing at a first junctionpoint into a first fluid passage and a second fluid passage downstreamof said source, said first fluid passage and said second fluid passagebeing joined together to re-establish said fluid conduit at a secondjunction point further downstream from said source; a turbine having aninlet and outlet communicating with said first fluid passage, saidturbine defining between said inlet and outlet a relatively convergent,divergent, and convergent flow path for fluid passing therethrough; acam-like control element within said turbine for changing the area andcurvature of said flow path;

and, ejector nozzle means embodied in said second fluid passage at saidsecond junction point, said ejector nozzle means acting to. create apressure difierential urging flow through said first fluid passagetowards said second junction point.'

7. The combination of: an internal combustion engine having acarburetor, an air-fuel intake manifold and an exhaust manifold; aturbo-supercharger associated with said engine, said turbo-superchargercomprising a hollow casing containing both air compressing means. andturbine means; said turbo-supercharger having an air-fuel inlet forpressure sealed mounting on an outlet end of said carburetor and anair-fuel outlet for pressure seal mounting on an air-fuel inlet portionof said air-fuel intake manifold, a portion of said exhaust manifoldbeing divided at a first given junction point to form a first fluidpassage and a second fluid passage, said first fluid passage and saidsecond fluid passage being joined together at a second given junctionpoint downstream of said first given junction point to re-establish saidexhaust manifold, said turbo-supercharger being interposed in and havingan inlet and outlet communicating with said first fluid passage wherebysaid turbine means is driven by gas flowing through said first fluidpassage, said turbosupercharger defining between said inlet and saidoutlet a relatively convergent, divergent, and convergent flow path forexhausting gas passing therethrough; and, a camlike control elementwithin said casing for changing the area and curvature of said flowpath.

8. The combination according to claim 7, and ejector nozzle meansembodied in said second fluid passage at said second junction point,said ejector nozzle means acting to create a pressure differentialurging flow through said first fluid passage towards said secondjunction point.

9. The combination according to claim 8, and adjust,- able means forvarying the effective area of said ejector nozzle means relative to agiven quantity and pressure of exhaust gas admitted thereto through saidsecond fluid passage.

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